We encountered this Giant Keyhole Limpet in the tidepools. We watched as it traveled across the rocks to get back into a pool. It was a large one. It was about 5 inches across and 8 inches long. The giant keyhole limpet is a flat-shelled gastropod. They are a type of mollusk. Simply put a sea snail. They have a foot, a head and gills. They have a radula that scrapes algae off the rocks for food. The hole in the shell serves many purposes. It is used to expel waste, water and also is used to spawn. They protect themselves by pushing their body over the shell so that they are very slippery making it difficult for a predator to get them. They are the biggest common snails in the tidepools in Southern California.

Body pushed up over shell.
Body starting to recede.
The final push to the water.
Blowing bubbles when it got underwater.